Tow cutter

ABSTRACT

A tow cutter wherein a tow of filaments to be cut is laced around radially extending pins mounted on a rotating drum in such a manner that the tow extends in a zigzag configuration around the drum with spans of the tow extending longitudinally along the periphery of the drum. A plurality of rotating cutters extend into spaced slots in the periphery of the drum to sever the tow into small lengths as the spans of tow are carried past the cutters. Flexible belts engage the periphery of the drum between the slots therein to hold the tow between the belt and the periphery of the drum as the cutting operation is carried out.

United I States Patent 1 Gamble I Oct. 30, I973 Tow CUTTER [75} Inventor: James G. Gamble, Danielson,

'TIII'I I".'""""'i" I'I'I 1," [73] Assignee: Monsanto Company, St. Louis,

I Mo.

[22] Filed: June 5, 1972 {21] Appl. No.: 259,892

[52! US. Cl. 83/411. R, 83/423 {5] Int. Cl B26d 7/06, B26d 4/04 [58] Field of Search 83/4II R, 423

[56] References Cited UNITED STATES PATENTS 3,238,825 3/l966 Dearsley 83/411 R X 3,303,733 2/l967 Medlycott et al 83/411 R X FOREIGN PATENTS OR APPLICATIONS 865,180 1/1953 Germany 83/41] R Primary Examiner-Willie G. Abercrombie Att0rneyRobert L. Broad, Jr. et al.

[5 7] ABSTRACT A tow cutter wherein a tow of filaments to be cut is laced around radially extending pins mounted on a rotating drum in such a manner that the tow extends in a zigzag configuration around the drum with spans of the tow extending longitudinally along the periphery of the drum. A plurality of rotating cutters extend into spaced slots in the periphery of the drum to sever the tow into small lengths as the spans of tow are carried past the cutters. Flexible belts engage the periphery of the drum between the slots therein to hold the tow be tween the belt and the periphery of the drum as the cutting operation is carried out.

5 Claims, 4 Drawing Figures 47 64 44 49 22 55 52 5/ l3 i J 22 ll 59 49 V I6 I" I,

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34 @7 Hip"; & t g 5; 50 m, I 'r w I5 n t i 'I (A l gene 0 56 4 F \l e 57 raiei i I 9 35 0 45 t as \@g PAIENIEDnm 30 I973 SHEU 3 BF 3 FIG. 3.

TOW CUTTER BACKGROUND OF THE INVENTION For many applications continuous man-made filaments must be cut into staple lengths. A number of cutters for carrying out this operation are known. Some of these cutters are efficient but have disadvantages such as a very high noise level. Others suffer from'a very short blade life, it being necessary in some cases to shut down the cutting machine at intervals of less than 30 minutes for resharpening or replacement of the blades. Others will cut one type of tow satisfactorily but cannot efficiently cut another type. For example, polyster tow seems to be much more difficult to cut than acrylic tow. With these problems in mind, one of the objects of this invention is to provide a novel and improved tow cutter.

. Another object of this invention is to provide a tow cutter having a very low noise level.

A still further object of this invention is to provide a tow cutter having a high rate of productivity.

Still another object of this invention is to provide a tow cutter wherein the tow is laid in spans lying longitudinally along the periphery of a rotating drum and the tow is cut into staple lengths by a plurality of cutters extending into slots in the periphery of the drum.

Other objects and advantages of the invention will become apparent when the following detailed description is read in conjunction with the drawings in which FIG. 1 is a perspective view of the cutter of the present invention showing the general relationship of the various parts of one embodiment of the present invention,

FIG. 2 is an enlarged fragmentary side view showing the general relationship of the drum and that part of the machine which laces the tow onto the drum,

FIG. 3 is an enlarged fragmentary view showing the manner in which the tow is laced onto the pins in a rotating drum, and i FIG. 4 is an enlarged fragmentary view showing the manner in which the cutters and the drum cooperate to sever the tow. v

Referring now in detail to the drawing there is shown a base 11 above which is mounted a rotating drum 12 which is mounted on a shaft 13 driven by a gear box 15 action through a belt 16. The periphery of the drum 13 is provided with a plurality of spaced annular slots 17 as best illustrated in FIG. 3.

The drum 12 has secured to the ends thereof a plurality of pins 30 and 21, the pins 20 and 21 being spaced around the periphery of the drum 12 and extending radially therefrom. The pins 20, positioned at one end of the drum 12, are spaced 45 apart around the periphery of the drum 12; The pins 21, positioned at the other end of the drum 12, are also spaced 45 apart around the periphery of the drum and are between the pins 20, i.e., each pin 21 is positioned on a longitudinal bisector of the are from one pin 20 to another. Thus, as the drum 12 is rotated, the pins.20 and 21 will alternately pass a longitudinal line positioned adjacent to the drum. The purpose of the pins 20 and 21 is to hold a tow 22 which is to be laced onto the pins 20 and 21 and held thereon for cutting. The positioning of the pins 45 apart is not critical. This spacing is selected only for illustrative purposes.

A plurality of pulleys 26 and 27 are mounted on shafts 28 and 29, respectively, positioned as best shown in FIG. 2. The pulleys 26 and 27 carry elastic belts 21 and are so positioned that the elastic belts 31 engage the periphery of the drum 12 to hold the tow 22 in firm contact with the surface of the drum 12 between each of the slots 17. This is to prevent shifting of the tow during the cutting operation.

A shaft 34 mounted for rotation above the base 11 and driven by an electric motor 35 acting through a belt 36 carries a plurality of disc cutters 39. The cutters 39 are positioned to extend into the slots 17 inthe surface of the drum 12 (as best shown in FIG. 4) to cut the spans of the tow held on the drum. The cut tow drops into a chute 40 and is delivered to a packaging area (not shown) by a centrifugal fan 41. (FIG. 1

The tow 22 is laced onto the pins 20 and 21 on the drum 12 by a feed tube 44. The tube 44 is made up of an intermediate leg secured at right angles to end legs, the three legs defining a square-cornered Z. The feed tube 44 is mounted for rotation above the base 11 and is driven by a motor 45 acting through a belt 46, the axis of rotation of the tube 44 being coaxial with one of the end legs of the tube. A pair of feed rolls 49 ,withdraw the tow 22 from a container 50 (FIG. 1) and through guides 51 and 52 into the rotating feed tube 44. A disc 47 secured to the feed tube serves to protect operating personnel from the moving feed tube.

The feed rolls 49 are driven by a belt 55 connected to an output pulley 56 of a gear box 57 which is driven by a belt 58, the belt 58 passing over a pulley 59 secured to the rotating feed tube 44. Another output pulley 60 on the gear box 57 acts through a belt 61 to drive the gear box 15 and thereby rotate the drum 12.

The feed tube 44 is so positioned that the axis of rotation of the feed tube intersects the axis of rotation of the drum 12 at the midpoint thereof. The output end 64 of the feed tube 44 rotates in a plane tangent to the surface of the drum 12 so that the tow will engage the pins 20 and 21 on the drum as the feed tube 44 is rotated.

In operation, the feed rolls 49, withdraw the tow from I the container 50 and feed it into the end of the rotating feed tube 44. As the feed tube 44 and the drum 12 rotate in timed sequence the tow 22 is laced onto the pins 20 and 21 as best illustrated in FIG. 3. As the drum l2 advances the zigzagged spans of tow toward the cutter 39 the tow on the drum is engaged by the elastic belts 31 and held firmly in contact with the drum 12. Upon reaching the cutters 39 the tow is severed into short lengths as best illustrated in FIG. 4. The cut tow drops into the chute 40 and is withdrawn from the apparatus.

What is claimed is:

1. An apparatus for cutting a tow comprising a. a base,

b. a drum rotatably mounted above the base and having in the periphery thereof a plurality of annular slots, said drumalso having at the opposite ends thereof a plurality of pins for engaging and holding a tow of filaments to .be cut,

c. means mounted above the base for lacing the tow onto the pins on the drum in a zigzag pattern to form spans of the tow extending longitudinally along the surface of the drum, and

d. a plurality of spaced cutters mounted above the base and positioned to extend into the slots in the surface of the drum to cut the tow .lying on the surface of the drum as the drum is rotated.

2. The apparatus of claim 1 wherein the apparatus is provided with means adjacent to the drum for holding the tow in contact with the surface of the drum.

3. The apparatus of claim 2 wherein the means for holding the tow in contact with the drum comprises a plurality of flexible belts engaging the periphery of the drum, each of said belts being supported by a pair of spaced pulleys, said pulleys rotating on axes parrallel to the axis of the drum.

4. The apparatus of claim 2 wherein the lacing means comprises a Z-shaped tube having end legs connected to an intermediate leg, said tube being rotated about an axis coaxial with one of said end legs, the free end of the other end leg being positioned to move in a plane tangent to the drum.

5. Apparatus for cutting a tow comprising a. a base,

b. a drum rotatably mounted above the base and having in the periphery thereof a plurality of spaced annular slots, said drum also having at the opposite ends thereof a plurality of radially extending pins for engaging and holding a tow of filaments to be cut, said pins at one end of the drum being positioned between the pins at the other end of the drum so as to hold the tow in a zigzag pattern along the surface of the drum,

0. a plurality of pairs of spaced pulleys positioned adjacent to the drum,

d. a plurality of flexible belts each extending around one pair of the pulleys, said pulleys being so positioned that the belts are held in contact with the surface of the drum to thereby hold the tow against the drum,

. A Z-shaped tube having end legs connected to an a plurality of disc cutters positioned adjacent to the drum, each of said cutters extending into one of the slots in the drum for severing the tow lying on the surface of the drum, and

g. means for feeding the tow into the end of said one end leg. 

1. An apparatus for cutting a tow comprising a. a base, b. a drum rotatably mounted above the base and having in the periphery thereof a plurality of annular slots, said drum also having at the opposite ends thereof a plurality of pins for engaging and holding a tow of filaments to be cut, c. means mounted above the base for lacing the tow onto the pins on the drum in a zigzag pattern to form spans of the tow extending longitudinally along the surface of the drum, and d. a plurality of spaced cutters mounted above the base and positioned to extend into the slots in the surface of the drum to cut the tow lying on the surface of the drum as the drum is rotated.
 2. The apparatus of claim 1 wherein the apparatus is provided with means adjacent to the drum for holding the tow in contact with the surface of the drum.
 3. The apparatus of claim 2 wherein the means for holding the tow in contact with the drum comprises a plurality of flexible belts engaging the periphery of the drum, each of said belts being supported by a pair of spaced pulleys, said pulleys rotating on axes parrallel to the axis of the drum.
 4. The apparatus of claim 2 wherein the lacing means comprises a Z-shaped tube having end legs connected to an intermediate leg, said tube being rotated about an axis coaxial with one of said end legs, the free end of the other end leg being positioned to move in a plane tangent to the drum.
 5. Apparatus for cutting a tow comprising a. a base, b. a drum rotatably mounted above the base and having in the periphery thereof a plurality of spaced annular slots, said drum also having at the opposite ends thereof a plurality of radially extending pins for engaging and holding a tow of filaments to be cut, said pins at one end of the drum being positioned between the pins at the other end of the drum so as to hold the tow in a zigzag pattern along the surface of the drum, c. a plurality of pairs of spaced pulleys positioned adjacent to the drum, d. a plurality of flexible belts each extending around one pair of the pulleys, said pulleys being so positioned that the belts are held in contact with the surface of the drum to thereby hold the tow against the drum, e. A Z-shaped tube having end legs connected to an intermediate leg, said tube being mounted above the base for rotation about an axis coaxial with one of one said end legs, said axis intersecting the axis of rotation of the drum, the free end of the other end leg being positioned to move in a plane tangent to the drum, f. a plurality of disc cutters positioned adjacent to the drum, each of said cutters extending into one of the slots in the drum for severing the tow lying on the surface of the drum, and g. means for feeding the tow into the end of said one end leg. 